1. Field of the Invention
This invention relates to an aeration or breathing apparatus and, in particular, for gas masks and/or protective clothing where the aeration or breathing apparatus produces the pressure required to overcome fluid flow resistance and/or produce a pressure or an overpressure in the apparatus.
2. Description of the Prior Art
Gas masks are generally known as BC gas masks. The purpose of these masks is to produce harmless and breathable air from contaminated ambient air. For this purpose, there are filters in the breathing passages of the gas mask. The filters are customarily activated carbon filters. To overcome fluid flow resistance of such filters, the user must apply so much energy that the use of gas masks is very strenuous. To overcome this flow resistance, the prior art includes the use of auxiliary aeration equipment. Such auxiliary aeration equipment comprises a fan, which is preferably located behind the filter, and therefore acts as a suction fan and pulls the breathing air through the filter. Optionally, the suction draft or flow can be adjusted so that an overpressure develops in the gas mask in relation to the ambient atmosphere.
For the operation of an aeration or breathing apparatus, German Laid Open Patent Application No. 35 23 097 proposes the use of batteries. In that case, for the evaluation of a battery, its weight coefficient is a criterion of particular importance. The weight coefficient is the current supplied, taking the weight of the battery into consideration.
German Utility Model No. G84 36 184 discloses a housing for energy supply units which have batteries, whereby this housing is designed as an element to provide protection against a possible overpressure inside the housing, with a closing by means of a rupture disc and an aeration hole.
U.S. Pat. No. 4,484,691 discloses the manufacture of lithium batteries with a metal jacket, which has a predetermined breaking point.